Disconnecting switch



A. B. DE GICRG! DISCONNECTING SWITCH July 18, 1933.

Filed April 8, 1929 2 Sheets-Sheet 1 July 18, 193-3. I A. 5. DE- GIORGI 7 1,918,741

DI SCONNECTING SWITCH Filed April 8, 19 29 2 Sheets-Sheet 12 Patented July 18, 1933 ACB'ILLE BAGNAGATTI DE GIORGI, OF MILAN, ITALY DISCONNECTTNG SWITCH Application filed April 8,

The present invention relates to a disconnecting switch for high tension lines.

Switches of this nature are inserted in electric lines to permit one section of the line to become isolated from another section, or for permitting the isolation of the apparatus fitted on a line in the event of repairs, inspections, etc. They I v switch arm operable from a distance, and mounted on a center column in such a manner that the arm ends canbe moved into or out of touclrwith contacts carried on other columns mounted on a base-plate. Apparatuses of this kind heretofore known exhibit several inconveniences, by which their working and efliciency is impaired.

One of'the inconveniences arises from the formation of ice on the knife contacts usually used in devices of this character. This accumulation of ice increases the resistance encountered in opening and closing the contacts.

During closing of the switch arm considerable stresses are exerted on the ends of the isolating columns, at right angles to the columns themselves. These stresses give rise to tension stresses in the porcelain as a consequence of the high bending moment deriving from the length of the isolating column. Especially in view of the m dern tendency to standardization of the insulators, this is a serious drawback, since it is no longer practicable to design the insulator as a solid uniform resistance to flexion.

These and other inconveniences of the separating switches heretofore used are removed by the present invention, the subject matter of which is essentially distinguished by the fact that the ends of the. swinging switch arm carry contact brushes adapted to move relatively to the arm and bearing, when in close position, against preferably vertical contact surfaces carried by the isolating columns, so that upon initial rotation of the arm carrying column, through the medium of a suitable gear the brushes disengage the contact surfaces and then the swinging of'arm takes place, the sequence being the reverse in the closing operation.

It will be understood that the denominations of brushes and contact surfaces, accordcomprise a swinging d the body 1929, Serial No. 353,503, and in Italy April 12, 1928.

ing to the spirit of the invention are applied to equivalent constructive elements.

Owing to the above mentioned initial disengagement of the brushes from the contacts, long arms such as used with high tension lines can be conveniently manipulated.

The accompanying drawings diagrammatically illustrates one embodiment of the invention by way of example only.

Fig. 1 is a longitudinal elevation, partly in section, showing the switch in closed position.

Fig. 2 is a horizontal section along the line 2-2 in Fig. 1.

Fig. 3 is a fragmentary plan view partly in elevation, showing the switch closed.

Fig. 4 is a similar view showing the switch in open position.

Fig. 5 is a part horizontal section on the line 55 in Fig. 1.

The numeral 1 in the base plate; 2 the center isolating column carrying the arm and connected to the actuating gear 4 which may be of any known type; 55 are the end isolating columns carrying the stationary contacts 6-6.

In the shell-shaped frame 7 including the arm 3, the movable contact. brushes 88 are mounted, while the corresponding stationary contacts 6-6 present to the brushes substan tially vertical surfaces 9 which are particularly advantageous inasmuch as they avoid the accumulation of moisture.

Each brush 8 comprises a guide body 10 secured to the ends of the arm and in which slides a piston 12 which is acted upon by a spring 13; through the spring13,in'terposed between the piston and one end of the body the piston 12 exerts a pressure on the end of 10 and tends to urge the piston 12 inwardly during opening ofthe switch. The pistons 12 are connected by links 1414 to cranks 15 solid with the spindle 16 of the arm 3, so that when the arm spindle is turned through an angle, the cranks 15 are turned along with it and draw in and push outwardly, the connecting links 14 which will therefore impart an axial movement to the brushes 8. The ends of the arm frame 7 have mounted thereon hoods 17, indicated in the drawings indicates dotted lines in Figs. 2, 3 and 4, which protect the contacting parts against atmospheric agents, while below they are fitted with pins and rollers 18; in closing position the pins and rollers pass behind contact surfaces 19 of the stationary contacts 6, so that they neutralize the axial thrust exerted by the brushes 8 when the brushes move towards the said contact surfaces, and also dampen the shock of the rotating system.

The working of the separating switch according to the invention is as follows:

When the switch is closed, the brushes 8 (Figs. 1 and 2) completely adhere to the contact surfaces 19. When the opening movement is started, the center column 2 begins to revolve and therewith also the spin dle 16 of the arm 3. The cranks 15 now take up the position 15 in which they are shown in Fig. 3 and consequently draw the connecting links 14 into the position 14 and at which time the cranks engage the projections 21.

. As a consequence the pistons 12 take up the positions 12 and, due to the presence of the inwardly turned edge 20 of the cylinders 11, they drag the brush body 10 and the brush which will disengage from the contact surface 19 and take the ing motor goes on exerting its action, and since the cranks 15 engage the projection 21 fixed to the needle frame 7 and the rotating movement is thus transmitted to the needle 3 which will take up the opening position 3 (Fig. 4). A movement in the opposite direction takes place in the closing operation. It will be obvious that when the switch is closed and the brushes are in contact with the flat surface 19, the springs 13 will be compressed and will expand as soon as the cranks move beyond a dead center, thus shifting the pistons inwardly previous to the engagement of the cranks with the projections 21. Thus it will be seen that the brushes are initially moved inwardly in a straight lineal direction and out of contact with the surface 19 before the cranks break joint and before the arm begins to swing for its opening position.

The apparatus is provided with a dampin device 22, such as an air brake or the like, the stem 23 of which is connected to an arm 24 tacts, cran position 8. As the openfixed on the bottom pin 25 of the center column 2.

Obviously the details in the embodiment of the invention may be varied in any desired manner within the spirit and scope of the invention.

What I claim and desire to secure by United States Letters Patent is:

1. A switch of the class described comprising a pair of spaced stationary insulators having stationary contacts thereon, a rotatable insulator between the stationary insulators, an arm rotatable with the rotatable insulator having guide bodies at its ends, pistons. slidably guided in said bodies and having brushes movable therewith, springs in the cylinders urging said brushes from yieldable engagement with the stationary conis associated with the rotating insulator, links connecting the pistons and cranks, and means for rotating the rotatable insulator for sliding the pistons to cause the brushes carried thereby to move in an axial direction to disengage the stationary contacts before swinging movement is imparted to the arm and to swing the arm only after full disengagement of the contacts and brushes.

2. A switch of the class described comprising a pair of stationary insulators having flat faced stationary contacts thereon, a rotatable insulator between the stationary insulators, a switch arm rotatable with the rotatable insulator and having guide bodies in its ends, pistons slidably guided in said bodies, brushes carried by and movable with the pistons, springs between the pistons and outer ends of the bodies adapted to urge the brushes from engagement with the flat faced contact when'the switch is opening, cranks carried by the rotatable insulator, links connecting the cranks and pistons, stops carried by the arm, means for rotating the rotatable insulator to first actuate the links to cause the pistons to withdraw the movable brushes from engagement with the stationary contacts and to cause one of said cranks to engage said stops to swing the arm only after axial movement is imparted to the pistons and to disengage the contacts and brushes.

ACHILLE BAGNAGATTI DE GIORGI. 

